1. Field of the Invention
The present invention relates to an optical switch, and particularly to an optical switch having an indicating device for indicating an operational state of each output port of the optical switch.
2. Description of Related Art
Optical signals are commonly transmitted in optical fibers, which provide efficient light channels through which optical signals can pass. Recently, optical fibers have been used in various fields, including telecommunications, where light passing through an optical fiber is used to convey either digital or analog information. Efficient switching of optical signals between individual fibers is necessary in most optical processing systems or networks to achieve the desired routing of the signals.
In optical fiber systems, various methods have been previously developed for switching optical signals between fiber cables. U.S. Pat. No. 4,705,349 discloses an optical switching device comprising a first port, a second port, a third port, a mounting fixture, a planar mirror and a rotatable table. The mirror is rigidly attached to the rotatable table, which is rotatably mounted upon the mounting fixture. Optical signals are switched among the three ports by selectively rotating the rotatable table. However, no visual indication is provided to an operator showing the operational state of each port of the optical switching device.
For the above reason, an improved optical switch is desired which has an indicating device for indicating an operational state of every output port of the optical switch.
An object of the present invention is to provide an improved optical switch having an indicating device for indicating an operational state of each output port of the optical switch.
An optical switch in accordance with the present invention comprises a housing, an input port, a plurality of output ports, an optical switching means, an indicating device and a driving device.
The optical switching means includes a base, a carrier, a fixed reflector and a movable reflector. The base defines a receiving slot and a plurality of base holes. The fixed reflector is fixed in the receiving slot and is aligned with the input port. The movable reflector is attached to an upper surface of the carrier. A pole is mounted in the receiving slot of the base. The carrier is mounted to and can move along the pole.
The optical switch further comprises a wiper contact and a resistor. The wiper contact is fixed to the carrier and maintains contact with the resistor, which is fixed relative to the base. The indicating device includes a plurality of light emitting components.
In use, the driving means drives the carrier to a position aligned with a desired output port. A light beam traveling through the input port hits the fixed reflector and is reflected to the movable reflector. The movable reflector directs the light beam to the desired output port. As the carrier moves along the pole, the wiper contact slides along the surface of the resistor and thereby alters the resistance provided in a control circuitry (not shown). As a result, the control circuitry provides control signals which turn on a light emitting component corresponding to the output port.
Other objects, advantages, and novel features of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.